This invention relates generally to thermoplastic containers, and more particularly to a new and improved hinge means for blow-molded cases.
Blow-molded containers are commonly used in packaging articles which require some measure of protection against shock and abuse during storage and shipping.
Often, these blow-molded containers are of double wall construction to enhance the cushioning effect of the container while also providing shaped areas of the article to be carried in the container. Typically, these containers are blow-molded into a cover portion, a body portion, and an integral hinge arrangement. Alternately, the body portion and cover portion are separately molded, and a hinge may either be formed integrally on each portion, or may be separately attached to each portion to provide a hinge means for opening and closing the container after joining the body portion and cover portion.
One such example of a container with discrete body and cover portions is described in U.S. Pat. No. 4,005,800 (Schurman) which describes a container in which a cover portion has an integral hinge with a pair of hinge pins extending from either end thereof, and a body portion having receiving means for the hinge pins.
U.S. Pat. No. 4,078,657 (Schurman) describes a similar arrangement.
Also of interest is U.S. Pat. No. 4,211,337 (Weavers et al) which describes a plastic box having an integral hinge on one part of the box having two separate and spaced apart spines with a pin on each spine projecting toward the outside edge of the container. The other part of the box contains a projection which fits between the two spines of the first part of the box, as well as receiving means for the pins.
These and similar designs make use of integral hinge means in which the total configuration of the hinge means of a cover part and a body part of a plastic container are radically different in design. It would be highly desirable for the sake of economy and simplicity to provide a hinge arrangement in which the body portion and cover portion of a thermoplastic container were essentially identical, or at least similar, particularly with respect to the hinged area of the container.
The prior designs also have the problem of some difficulty in actual assembly of the two halves of the thermoplastic container. It would therefore also be beneficial to provide a hinge arrangement wherein the two halves of the container, i.e. the body portion and cover portion could be relatively easily assembled while still providing a container in which, after assembly, the container is securely attached and permits opening and closing the container without the danger of separation of the body and cover portions.
It is, therefore, an objective of the present invention to provide a container in which both halves of the container have essentially the same, or at least similar, hinge configuration in order to provide simplified and economic tooling of the container parts.
It is also an objective of the present invention to provide a container in which the hinge configuration allows for relatively easy assembly yet provides a secure hinge after assembly which will not easily separate during use.